1. Field of the Disclosure
The present disclosure relates generally to a wireless communication system and, more particularly, to a method for a terminal to select a communication interface based on dynamically changed information.
Furthermore, the present disclosure relates to a method of recovering a lost packet without a reduction of throughput depending on the reason of a lost packet if the transmission control protocol (TCP) packet is lost.
Furthermore, the present disclosure relates to a method for providing virtual reality (VR) content in the same direction to a user regardless of a photographing direction if VR-related content is generated.
2. Description of Related Art
To meet the demand for wireless data traffic having increased since the deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a “beyond 4G network” or a “post LTE system”.
The 5G communication system is considered to be implemented in higher frequency (e.g., mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (mMIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam forming, and large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMPs), reception-end interference cancellation, etc.
In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.
If communication is performed through the 5G communication system, the communication speed is increased compared to the 4G communication system, but current consumption and costs may be increased. Accordingly, a user equipment (UE) requires a method of selecting an optimal communication interface (or radio access network (RAT)) according to circumstances by taking into consideration a user's preference, the state of the UE and/or the type of service used by the UE. In this case, parameters, such as a user's preference, the state of a UE and/or the type of service used by a UE, are dynamically changed. In a conventional technology, a method of selecting a RAT by taking into consideration such UE information is not present.
Accordingly, there is a need for a method of selecting the best RAT by taking into consideration a dynamically changed parameter.
Furthermore, if some TCP packets transmitting through the TCP protocol are lost, a UE may transmit selective acknowledgement (SACK), and a server may decrease a congestion window (CWND).
In this case, if the packets have not been lost due to congestion, it is not necessary to decrease the CWND, and there is a problem that throughput is unnecessarily decreased. Accordingly, there is a need for a method of recovering a lost packet without a reduction of throughput based on the reason of a lost packet.
Furthermore, if the photographing direction of a photographing device is changed when VR content is generated, there may be a problem in that a screen provided through a VR UE is rotated. Accordingly, there is a need for a method for providing VR content in the same direction regardless of the photographing direction.